Increasing seed lipid content by over-expressing transcriptional regulators

Abstract

Expression cassettes, plant cells, plant seeds, plants, and methods for modulating lipid content of seeds and growth of such plants. The expression cassette comprises a promoter operably linked to a nucleic acid segment encoding a polypeptide for MYBS2, bHLH093, ATHB25, DiV2, CESTA1, TGA4, SPL12, or AGL18, or a combination of two, three, four, five, six, seven or all thereof.

What is claimed is: 
     
         1 . A plant cell, plant seed, or plant comprising an expression system comprising an expression cassette comprising a promoter operably linked to a nucleic acid segment encoding a polypeptide for MYBS2, bHLH093, ATHB25, DiV2, CESTA1, TGA4, SPL12, or AGL18, or a combination of two, three, four, five, six, seven or all thereof. 
     
     
         2 . The plant cell, plant seed, or plant of  claim 1 , wherein the plant seed has approximately 10% to approximately 20% more seed lipid content than a corresponding wild-type plant seed. 
     
     
         3 . The plant cell, plant seed, or plant of  claim 1 , wherein:
 the polypeptide for MYBS2 has at least 95% sequence identity to SEQ ID NO: 1;   the polypeptide for bHLH093 has at least 95% sequence identity to SEQ ID NO: 3;   the polypeptide for ATHB25 has at least 95% sequence identity to SEQ ID NO: 5;   the polypeptide for DiV2 has at least 95% sequence identity to SEQ ID NO: 7;   the polypeptide for CESTA1 has at least 95% sequence identity to SEQ ID NO: 9;   the polypeptide for TGA4 has at least 95% sequence identity to SEQ ID NO: 11;   the polypeptide for SPL12 has at least 95% sequence identity to SEQ ID NO: 13; and   the polypeptide for AGL18 has at least 95% sequence identity to SEQ ID NO: 15.   
     
     
         4 . The plant cell, plant seed, or plant of  claim 3 , wherein the nucleic acid segment encodes an inactivating mutant of the polypeptide for MYBS2, bHLH093, ATHB25, DiV2, CESTA1, TGA4, SPL12, or AGL18. 
     
     
         5 . The plant cell, plant seed, or plant of  claim 4 , wherein the plant seed has approximately 7.2% to approximately 18% less seed lipid content than a corresponding wild-type plant seed. 
     
     
         6 . The plant cell, plant seed, or plant of  claim 1 , wherein the plant cell, plant seed, or plant is an oil crop plant cell, plant seed, or plant. 
     
     
         7 . The plant cell, plant seed, or plant of  claim 6 , wherein the oil crop is a  Brassica  species, camelina, soybean, corn, sunflower, cotton, peanut, or avocado. 
     
     
         8 . The plant cell, plant seed, or plant of  claim 7 , wherein the  Brassica  plant species is  Brassica rapa, Brassica juncea, Brassica napus , or  Brassica carinata.    
     
     
         9 . The plant cell, plant seed, or plant of  claim 1 , wherein the promoter is a strong or inducible promoter. 
     
     
         10 . The plant cell, plant seed, or plant of  claim 1 , wherein the promoter is a tissue-specific promoter. 
     
     
         11 . The plant cell, plant seed, or plant of  claim 1 , wherein the promoter is selected from a cauliflower mosaic virus promoter (such as CaMV 35S or CaMV 19S), nos promoter, Adh1 promoter, sucrose synthase promoter, α-tubulin promoter, ubiquitin promoter, actin promoter (such as from rice), cab promoter, PEPCase promoter, R gene complex promoter, poplar xylem-specific secondary cell wall specific cellulose synthase 8 promoter, Z10 promoter from a gene encoding a 10 kDa zein protein, Z27 promoter from a gene encoding a 27 kDa zein protein, pea rbcS gene, and phaseolin promoter. 
     
     
         12 . An expression cassette comprising a promoter operably linked to a nucleic acid segment encoding a polypeptide for MYBS2, bHLH093, ATHB25, DiV2, CESTA1, TGA4, SPL12, or AGL18, or a combination of two, three, four, five, six, seven or all thereof. 
     
     
         13 . The expression cassette of  claim 12 , wherein the promoter is selected from a cauliflower mosaic virus promoter (such as CaMV 35S or CaMV 19S), nos promoter, Adh1 promoter, sucrose synthase promoter, α-tubulin promoter, ubiquitin promoter, actin promoter (such as from rice), cab promoter, PEPCase promoter, R gene complex promoter, poplar xylem-specific secondary cell wall specific cellulose synthase 8 promoter, Z10 promoter from a gene encoding a 10 kDa zein protein, Z27 promoter from a gene encoding a 27 kDa zein protein, pea rbcS gene, and phaseolin promoter. 
     
     
         14 . The expression cassette of  claim 12 , wherein the promoter is a strong or inducible promoter. 
     
     
         15 . The expression cassette of  claim 12 , wherein the promoter is a tissue-specific promoter. 
     
     
         16 . The expression cassette of  claim 12 , wherein:
 the polypeptide for MYBS2 has at least 95% sequence identity to SEQ ID NO: 1;   the polypeptide for bHLH093 has at least 95% sequence identity to SEQ ID NO: 3;   the polypeptide for ATHB25 has at least 95% sequence identity to SEQ ID NO: 5;   the polypeptide for DiV2 has at least 95% sequence identity to SEQ ID NO: 7;   the polypeptide for CESTA1 has at least 95% sequence identity to SEQ ID NO: 9;   the polypeptide for TGA4 has at least 95% sequence identity to SEQ ID NO: 11;   the polypeptide for SPL12 has at least 95% sequence identity to SEQ ID NO: 13; and   the polypeptide for AGL18 has at least 95% sequence identity to SEQ ID NO: 15.   
     
     
         17 . A method of growing a plant seed or plant comprising:
 introducing into at least one plant cell at least one transgene or expression cassette encoding a polypeptide for MYBS2, bHLH093, ATHB25, DiV2, CESTA1, TGA4, SPL12, or AGL18, or a combination of two, three, four, five, six, seven or all thereof, to generate one or more transformed plant cells; and   generating a plant from the one or more transformed plant cell(s).   
     
     
         18 . The method of  claim 17 , wherein:
 the polypeptide for MYBS2 has at least 95% sequence identity to SEQ ID NO: 1;   the polypeptide for bHLH093 has at least 95% sequence identity to SEQ ID NO: 3;   the polypeptide for ATHB25 has at least 95% sequence identity to SEQ ID NO: 5;   the polypeptide for DiV2 has at least 95% sequence identity to SEQ ID NO: 7;   the polypeptide for CESTA1 has at least 95% sequence identity to SEQ ID NO: 9;   the polypeptide for TGA4 has at least 95% sequence identity to SEQ ID NO: 11;   the polypeptide for SPL12 has at least 95% sequence identity to SEQ ID NO: 13; and   the polypeptide for AGL18 has at least 95% sequence identity to SEQ ID NO: 15.   
     
     
         19 . The method of  claim 17 , further comprising harvesting lipids from the seeds of the mature plant. 
     
     
         20 . The method of  claim 17 , wherein the promoter is a strong or inducible promoter. 
     
     
         21 . The method of  claim 17 , wherein the promoter is a tissue-specific promoter. 
     
     
         22 . The method of  claim 17 , wherein the promoter is selected from a cauliflower mosaic virus promoter (such as CaMV 35S or CaMV 19S), nos promoter, Adh1 promoter, sucrose synthase promoter, α-tubulin promoter, ubiquitin promoter, actin promoter (such as from rice), cab promoter, PEPCase promoter, R gene complex promoter, poplar xylem-specific secondary cell wall specific cellulose synthase 8 promoter, Z10 promoter from a gene encoding a 10 kDa zein protein, Z27 promoter from a gene encoding a 27 kDa zein protein, pea rbcS gene, and phaseolin promoter. 
     
     
         23 . The method of  claim 17 , wherein the plant seed or plant is an oil crop. 
     
     
         24 . The method of  claim 23 , wherein the oil crop is a  Brassica  plant species, camelina, soybean, corn, sunflower, cotton, peanuts, or avocado. 
     
     
         25 . The method of  claim 24 , wherein the  Brassica  plant species is  Brassica rapa, Brassica juncea, Brassica napus , or  Brassica carinata.    
     
     
         26 . The method of  claim 17 , wherein the nucleic acid segment encodes an inactivating mutant of the polypeptide for MYBS2, bHLH093, ATHB25, DiV2, CESTA1, TGA4, SPL12, or AGL18. 
     
     
         27 . The method of  claim 26 , further comprising harvesting starch from the seeds of the mature plant.